The present invention relates generally to golf applications, and more particularly to a golf club. More specifically, a golf club head of the golf club has at least one or more portions including at least one mid-density material having a density ranging from 4.5 g/cm3 to 7.9 g/cm3 which provide sufficient stiffness at a reduced weight to optimize the center of gravity and moment of inertia of the golf club head. Also, by using mid-density materials, discretionary weight of the golf club head is increased which can be used to position higher density weights at selective portions of the golf club head.
Materials used in the construction of golf clubs have varying densities. This range includes from 1.8 g/cm3 for carbon fiber composites to tungsten based materials having density of 18.5 g/cm3. However the most common materials used are metallic materials such as steels and titanium alloys having a density of about 7.9 g/cm3 and 4.5 g/cm3 respectively.
Most golf clubs are made from steel or titanium alloys, and over the many decades of golf club manufacture other materials have been used such as brass, copper, bronze, aluminum, plastics, fiberglass, composites, and, of, course, wood. These materials generally have densities either at or lower than titanium, or at or above steel.
With the exception of carbon fiber composites, materials lighter than titanium typically have fairly low stiffness, and are therefore generally unsuitable for use in most types of golf clubs because their low inherent stiffness generate low frequency vibrations when impacting a golf ball. Low frequency vibrations are considered “bad feel” and “bad sound” for a golf club. Materials heavier than steel usually have good stiffness, but are generally too heavy to be used for anything but discretionary weights in golf.
Therefore, it would be advantageous in golf club design to provide a golf club head having at least one or more portions made of mid-density materials having a density ranging from 4.5 g/cm3 to 7.9 g/cm3, between titanium and steel, which provide sufficient stiffness at a reduced weight to optimize the center of gravity and moment of inertia of the golf club head.